Nonlinear circular valley photogalvanic effect

We develop a theory of circular photogalvanic effect in nongyrotropic two-dimensional transition metal dichalcogenide monolayers under interband optical transitions. Oblique incidence of circularly polarized electromagnetic field or normal incidence of elliptically polarized electromagnetic field is assumed. In contrast to the linear-in-intensity conventional photogalvanic effect, the effect considered here arises in the second intensity order. The effect is conditioned by (i) the predominant population of the valleys by the circular in-plane electromagnetic field component and (ii) the direct drift of the photoexcited carriers by the linear-polarized in-plane electromagnetic field component in the presence of trigonal valley asymmetry.

Automated summary

The theory explores the circular photogalvanic effect in nongyrotropic two-dimensional transition metal dichalcogenide monolayers, which arises in the second intensity order as opposed to the linear-in-intensity conventional photogalvanic effect. This effect is conditioned by two factors: the predominant population of the valleys by the circular in-plane electromagnetic field component, and the direct drift of the photoexcited carriers by the linear-polarized in-plane electromagnetic field component in the presence of trigonal valley asymmetry.